Compressing centrifuge with cooling

ABSTRACT

A method and apparatus for compressing gases wherein said gas is first compressed within a rotating centrifuge to a pressure that is higher than the pressure outside said centrifuge rotor cavity with said gas being discharged from said primary rotor via nozzles mounted near the periphery of said rotor; said nozzles being oriented to discharge said gas from said nozzles to a direction that is either forward, radial or backward; said gas being passed from said primary rotor to a secondary rotor with one or more rows of vanes or nozzles; said secondary rotor vanes or nozzles being arranged to convert the motive energy of said gas to work; said secondary rotor nozzles being arranged to discharge said gas backward; said secondary rotor vanes or nozzles also being arranged to accelerate said gas. After leaving said secondary rotor, said gas is passed to unit discharge. Said primary rotor is provided with cooling to limit temperature increase of said gas during compression within said primary rotor resulting in a lower rotational speed for said rotor, for a predetermined pressure differential within said rotor.

United States Patent [191 Eskeli 1 Mar. 25, 1975 1 COMPRESSING CENTRIFUGE WITH COOLING [76] Inventor: Michael Eskeli, 6220 Orchid Ln.,

Dallas,TeX. 75230 i [22] Filed: Apr. 12, 1972 [21] Appl. No.: 243,239

Primary Examiner-Henry F. Raduazo 57 ABSTRACT A method and apparatus for compressing gases 7 wherein said gas is first compressed within a rotating centrifuge to a pressure that is higher than the pressure outside said centrifuge rotor cavity with said gas being discharged from said primary rotor via nozzles mounted near the periphery of said rotor; said nozzles being oriented to discharge said gas from said nozzles to a direction that is either forward, radial or backward; said gas being passed from said primary rotor to a secondary rotor with one or more rows of vanes or nozzles; said secondary rotor vanes 0r nozzles being arranged to convert the motive energy of said gas to work; said secondary rotor nozzles being arranged to I 8 Claims, 2 Drawing Figures PATENTEU 3,872,668

FIG. I

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COMPRESSING CENTRIFUGE WITH COOLING BACKGROUND OF THE INVENTION This invention relates generally to devices for compressing gases by utilizing centrifugal force in a rotary machine.

Various devices have been used to compress gases. One large group uses centrifugal force to accelerate the gas in the impeller, then throwing the gas to the diffuser where the motive energy of said fluid is converted to pressure.

The main disadvantage of these conventional devices is their poor efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS In FIG. 1 is a cross section of the device. FIG. 2 is an end view of the same unit with a portion removed to show the interior of the compressor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS It is an object of this invention to provide a method and apparatus to compress gases from a lower pressure to a higher pressure.

Referring to FIG. 1, therein is illustrated a cross section of said compressor. is casing, 11 is secondary rotor, 12 is primary rotor, 13 is bearing and seal, 14 is secondary rotor shaft, 15 is bearing and seal, 16 is hollow shaft for said primary rotor 12, 17 is coolant entry to said hollow shaft 16, 18 is space for the fluid around secondary rotor 11, 19 is secondary rotor nozzle, 20 is primary rotor nozzle, 21 is coolant conduit, 22 is bearing support, 23 is bearing, 24 is coolant exit, 25 is gas entry to said primary rotor cavity, 26 and 29 are coolant conduits, 27 is gas exit from unit, 28 is vane in primary rotor cavity to assure that said gas will rotate with said rotor.

In FIG. 2, an end view of the same unit is shown. 10 is casing, 18 is space for said gas, 19 is secondary rotor nozzle, 11 is secondary rotor, 20 is primary rotor nozzle, 12 is primary rotor, 21 is coolant conduit, 28 is vane in primary rotor cavity, 24 is coolant exit opening, 22 is hearing support, 27 is gas exit from unit, 30 is unit base, 31 indicates direction of rotation for secondary rotor, and for primary rotor.

In operation, gas to be compressed enters said primary rotor via opening 25, and passes to said rotor cavity. After being compressed within said cavity by centrifugal action on said fluid by said rotating primary rotor, and with cooling being provided by said coolant being circulated within said coolant conduits, said gas leaves said primary rotor via nozzles 20 mounted on the periphery of said primary rotor; said nozzles may be arranged to discharge said fluid either forward, radially or backward direction. Said nozzles may be either converging, or converging-diverging type arranged to provide for highest attainable gas exit velocity from said nozzles for the available pressure differential. After leaving the said primary rotor, said gas is passed to said secondary rotor 11, wherein said gas is compressed by centrifugal action by said secondary rotor, after which said gas is discharged in backward direction from nozzles l9; impulse of said gas leaving said nozzles 19 will produce a torque on said secondary rotor; said torque is then passed out as work via secondary rotor shaft 14. Also, said gas may have a high velocity when entering said secondary rotor; said secondary rotor will convert said velocity energy of said moving gas to torque, and pass said torque out as work via said shaft 14. After leaving said secondary rotor, said gas is collected in space 18, and passed to unit exit 27. Said coolant enters said rotor shaft 16 via opening 17, and passes along said shaft to coolant conduit 29, and from there to conduits 21, and 26, and from there to shaft 16 and out via opening 24. Said coolant conduits may be arranged as shown in FIG. 1 and FIG. 2, or said conduits may be built within the walls of said primary rotor. Said conduits are normally provided with suitable fins to improve heat transfer capability. Power is supplied to said primary rotor shaft 16, and power is produced by secondary rotor 11. The two shafts, 16 and 14, are normally connected with a suitable power transmission device, such as a gear box, so that the power produced by said secondary rotor may be employed to drive said primary rotor, with additional power being supplied from an external source.

The nozzles employed in said secondary rotor have their exit ends sized and shaped to provide for highest attainable exit velocity for said gas leaving said nozzles, as attained by esentropic expansion. Said exit ends of said nozzles 19 may be either converging or converging-diverging type, as required for the gas being compressed, and the gas velocities being used. Alternately, the secondary rotor nozzles may have a nearly constant area; said nozzles being formed by vanes; this type arrangement is employed when the kinetic energy only of the gas leaving said primary rotor, is converted to work.

As an example, when compressing air to psia pressure, with entry air being at 14.7 psia and 80F temperature, the pressure within said primary rotor may be psia with air temperature of 80F thereby having constant temperature compression; the tangential velocity then is approx. 1,500 FPS, for said primary rotor; said air is then expanded to I00 psia in said primary rotor nozzles, resulting in nozzle exit velocity of approx. 870 FPS, forward relative to rotor; this means then an absolute air stream velocity of 2,370 FPS; for the primary rotor work input is 141 BTU/1b.; and for secondary rotor, work output is ll2 BTU/lb, with the kinetic energy being converted to work. Thence, net work input is for these operating conditions 29 BTU/lb. of air.

Appropriate and well known equipment, instrumentation and controls may be used with this device. They do not form a part of this invention and are not further described herein.

The casing of the unit may be closely fitted to rotor walls as indicated in FIG. 1. The space between the rotating rotor and the casing is then partially evacuated by centrifugal action on the gas by said rotor, resulting in reduced friction losses for said rotor. Inherently the compressing centrifuge of this invention may be used as a generator of heat, since the cooling fluid will leave the compressing centrifuge at a higher temperature than when it enters. Therefore, the cooling fluid may be throttled to provide for the most advantageous use of the compressing centrifuge in any given situation, including compression, heating or a combination thererof.

I claim:

1. A compressing centrifuge for compressing a gaseous fluid comprising:

a. a casing for containing said fluid and for providing support for rotor shafts and bearings; said casing having respective inlet and outlet ports for receiving said gaseous fluid to be compressed and for discharging the compressed fluid;

b. a first rotor shaft for power input needed to effect rotation of a primary rotor; said first shaft being journalled for rotation in bearings supported in said casing; said first shaft having first and second longitudinally extending cooling fluid passageways for conveying a cooling fluid therethrough;

c. a primary rotor for subjecting said gaseous fluid to a centrifugal force field; said primary rotor being mounted on said first shaft so as to rotate in unison with said first shaft; said primary rotor having an internal space with internal vanes defining respective cavities within said primary rotor for ensuring that any fluid within said primary rotor rotates with the same rotational speed as said primary rotor; said primary rotor being equipped with means for introducing the fluid to be compressed at the center of the primary rotor and having suitable restricted discharge passageways adjacent the periphery for discharging the compressed said gaseous fluid; said discharge passageways being smaller in cross sectional dimensions than the minimum cross sectional dimensions of the associated cavity for ensuring that the fluid within the respective cavities of the rotating primary rotor will be subjected to centrifugation and centrifugal compression for effecting at the periphery of the rotor and upstream of the discharge passageways a compressed fluid having a second pressure that is higher than the pressure at the inlet to said primary rotor;

d. a cooling means disposed interiorly of said primary rotor so as to rotate in conjunction therewith; said cooling means comprising at least a peripherally disposed cooling passageway and respective radially extending passageways that are connected at their respective ends with said cooling fluid passageways in said first shaft so as to effect passage of said cooling fluid through said first passageway, through said cooling means in heat exchange relationship with the compressed gaseous fluid of said primary rotor and back to said second passageway for discharge of the heated cooling fluid; said cooling means having sufficient cooling surface to effect in conjunction with predetermined design conditions of inlet and outlet temperatures and flow rates of said cooling fluid nearly isothermal centrifugal compression of said fluid in said primary rotor;

. a second shaft journalled for rotation in bearings supported by said casing; said second shaft being adapted for conveying power from said secondary rotor;

f. a second rotor mounted for rotation on said second shaft for absorbing and converting to useful work a large portion of the kinetic energy of the fluid being discharged from its compressed fluid state through the discharge passageways of said primary rotor; said secondary rotor being fixed to said secondary shaft so as to rotate in unison therewith and to transmit power thereto; said secondary rotor having suitable vane means for absorbing energy from the fluid stream as it leaves the discharge passageways of said primary rotor; said secondary rotor being adapted to rotate in the same direction as said primary rotor.

2. The compressing centrifuge of claim 1 wherein said casing is fitted so closely to the external walls of respective said rotors that centrifugal action on fluid particles will partially evacuate the space between said casing and said rotor walls to reduce the fluid friction and allow said rotors to rotate more freely for more efficient operation.

3. The compressing centrifuge of claim 1 wherein said restricted discharge passageways of said primary rotor define means for effecting isentropic expansion of said fluid passing therethrough.

4. The compressing centrifuge of claim 1 wherein said restricted discharge passageways are at least converging at their discharge end section.

5. The compressing centrifuge of claim 1 wherein said restricted discharge passageways are diverging at their discharge end section.

6. A method of compressing a first gaseous fluid and simultaneously heating a second fluid comprising:

a. subjecting said first fluid to a centrifugal force field via a primary rotor having vanes defining cavities to ensure that the fluid attains the same rotational speed as said rotor, in a compressing centrifuge to compress the fluid to a pressure that is higher at the periphery of said primary rotor than at the entry thereto and is higher than the discharge pressure from the compressing centrifuge;

cooling the compressed said fluid interiorly of said rotor by circulating said second fluid at an adjustable flow rate along the axis of rotation of said primary rotor, radially outwardly and within said primary rotor and adjacent the periphery of said primary rotor in heat exchange relationship with the compressed said first fluid to heat said second fluid to a predetermined operational temperature commensurate with a predetermined resultant cooling of said first fluid during centrifugal compression; and passing the heated said second fluid radially inwardly to be discharged along the axis of rotation of said primary rotor;

c. passing said first fluid in its cooled, compressed state through discharge passageways that are smaller in cross sectional area than the minimum area of the respective associated cavities intermediate said vanes upstream of the discharge passageways and, thence, to a secondary rotor in which a large portion of the kinetic energy contained in the discharged fluid is extracted and converted to useful work; and

d. passing said fluid from said secondary rotor to an outlet of said centrifugal compressor; the pressure of said fluid at said outlet of said centrifugal compressor being higher than at the inlet to said centrifugal compressor.

7. The method of claim 6 wherein substantially isothermal centrifugal compression of said first fluid is effected with very little increase in the temperature of said second fluid.

8. The method of claim 6 wherein said second fluid is circulated at a reduced flow rate for effecting a substantial increase in its enthalpy and less efficient compression of said first fluid is effected.

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1. A compressing centrifuge for compressing a gaseous fluid comprising: a. a casing for containing said fluid and for providing support for rotor shafts and bearings; said casing having respective inlet and outlet ports for receiving said gaseous fluid to be compressed and for discharging the compressed fluid; b. a first rotor shaft for power input needed to effect rotation of a primary rotor; said first shaft being journalled for rotation in bearings supported in said casing; said first shaft having first and second longitudinally extending cooling fluid passageways for conveying a cooling fluid therethrough; c. a primary rotor for subjecting said gaseous fluid to a centrifugal force field; said primary rotor being mounted on said first shaft so as to rotate in unison with said first shaft; said primary rotor having an internal space with internal vanes defining respective cavities within said primary rotor for ensuring that any fluid within said primary rotor rotates with the same rotational speed as said primary rotor; said primary rotor being equipped with means for introducing the fluid to be compressed at the center of the primary rotor and having suitable restricted discharge passageways adjacent the periphery for discharging the compressed said gaseous fluid; said discharge passageways being smaller in cross sectional dimensions than the minimum cross sectional dimensions of the associated cavity for ensuring that the fluid within the respective cavities of the rotating primary rotor will be subjected to centrifugation and centrifugal compression for effecting at the periphery of the rotor and upstream of the discharge passageways a compressed fluid having a second pressure that is higher than the pressure at the inlet to said primary rotor; d. a cooling means disposed interiorly of said primary rotor so as to rotate in conjunction therewith; said cooling means comprising at least a peripherally disposed cooling passageway and respective radially extending passageways that are connected at their respective ends with said cooling fluid passageways in said first shaft so as to effect passage of said cooling fluid through said first passageway, through said cooling means in heat exchange relationship with the compressed gaseous fluid of said primary rotor and back to said second passageway for discharge of the heated cooling fluid; said cooling means having sufficient cooling surface to effect in conjunction with predetermined design conditions of inlet and outlet temperatures and flow rates of said cooling fluid nearly isothermal centrifugal compression of said fluid in said primary rotor; e. a second shaft journalled for rotation in bearings supported by said casing; said second shaft being adapted for conveying power from said secondary rotor; f. a second rotor mounted for rotation on said second shaft for absorbing and converting to useful work a large portion of the kinetic energy of the fluid being discharged from its compressed fluid state through the discharge passageways of said primary rotor; said secondary rotor being fixed to said secondary shaft so as to rotate in unison therewith and to transmit power thereto; said secondary rotor having suitable vane means for absorbing energy from the fluid stream as it leaves the discharge passageways of said primary rotor; said secondary rotor being adapted to rotate in the same direction as said primary rotor.
 2. The compressing centrifuge of claim 1 wherein said casing is fitted so closely to the external walls of respective said rotors that centrifugal action on fluid particles will partially evacuate the space between said casing and said rotor walls to reduce the fluid friction and allow said rotors to rotate more freely for more efficient operation.
 3. The compressing centrifuge of claim 1 wherein said restricted discharge passageways of said primary rotor define meAns for effecting isentropic expansion of said fluid passing therethrough.
 4. The compressing centrifuge of claim 1 wherein said restricted discharge passageways are at least converging at their discharge end section.
 5. The compressing centrifuge of claim 1 wherein said restricted discharge passageways are diverging at their discharge end section.
 6. A method of compressing a first gaseous fluid and simultaneously heating a second fluid comprising: a. subjecting said first fluid to a centrifugal force field via a primary rotor having vanes defining cavities to ensure that the fluid attains the same rotational speed as said rotor, in a compressing centrifuge to compress the fluid to a pressure that is higher at the periphery of said primary rotor than at the entry thereto and is higher than the discharge pressure from the compressing centrifuge; b. cooling the compressed said fluid interiorly of said rotor by circulating said second fluid at an adjustable flow rate along the axis of rotation of said primary rotor, radially outwardly and within said primary rotor and adjacent the periphery of said primary rotor in heat exchange relationship with the compressed said first fluid to heat said second fluid to a predetermined operational temperature commensurate with a predetermined resultant cooling of said first fluid during centrifugal compression; and passing the heated said second fluid radially inwardly to be discharged along the axis of rotation of said primary rotor; c. passing said first fluid in its cooled, compressed state through discharge passageways that are smaller in cross sectional area than the minimum area of the respective associated cavities intermediate said vanes upstream of the discharge passageways and, thence, to a secondary rotor in which a large portion of the kinetic energy contained in the discharged fluid is extracted and converted to useful work; and d. passing said fluid from said secondary rotor to an outlet of said centrifugal compressor; the pressure of said fluid at said outlet of said centrifugal compressor being higher than at the inlet to said centrifugal compressor.
 7. The method of claim 6 wherein substantially isothermal centrifugal compression of said first fluid is effected with very little increase in the temperature of said second fluid.
 8. The method of claim 6 wherein said second fluid is circulated at a reduced flow rate for effecting a substantial increase in its enthalpy and less efficient compression of said first fluid is effected. 